Dynamics of the auroral Es layer during weak and strong disturbances in the magnetosphere

Abstract

The paper is dedicated to studying the dynamics of the auroral ionosphere at the level of the sporadic Es layer during magnetospheric disturbances. A new approach to this problem, proposed in the paper, uses the geomagnetic PC index, which is calculated using the magnetic data in the polar caps of the northern and southern hemispheres and manifests the geoefficiency of the interplanetary electric field. It is shown that variations in the sporadic electron concentration in the auroral Es layer could be related to changes in the PC index with a high degree of statistical reliability. However, the character of precipitations of sporadic particles into the ionosphere under high (PC > 2 mV/m) and low (PC < 2 mV/m) magnetic activity differs substantially. During strong magnetic disturbances and under intensified electric fields in the interplanetary environment, the intensity of particle precipitation from the magnetosphere into the E region of the high-latitude ionosphere is governed by the values of the PC magnetic index. During weak magnetic disturbances, short-time pulses of an increase in the PC values, caused by the variability in electric field in the magnetosphere, are the main factor in the occurrence of sporadic ionization in the Es layer.